<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <script>

        // #### 实现一个计数器函数，每次调用该函数返回一个递增的数字
        // const createCounter = function () {
        //     let count = 0;
        //     const fn = function () {
        //         return ++count
        //     };
        //     return fn
        // }
        const createCounter = () => {
            
            let count = 0

            const fn = () =>{
                
                return count++
            }
            return fn
        }

        const counter = createCounter();
        console.log(counter()); // 1
        console.log(counter()); // 2
        console.log(counter()); // 3

        
    </script>
</body>

</html>